This invention relates to marine systems, and provides an apparatus and method for making dry, oil-free utility air and inert gas, for use on a marine vessel.
Commercial ships require utility air, for various purposes, and often also require inert gas for use in a cargo storage area. Utility air must be free of liquids, such as oil or water, to avoid plugging of air lines and fouling of pneumatic instruments.
In the prior art, utility air for a ship has been typically produced by directing ambient air into a compressor, and then passing the compressed air through one or more refrigeration dryers and one or more filters.
Also in the prior art, an inerting gas has been typically produced by inert gas generators (IGGs) which use the combustion gas from the burning of diesel fuel to make a gas having a low oxygen content.
The inert gas generators of the prior art have several disadvantages. The combustion gas can be very corrosive, because it generally includes sulfuric acid and carbonic acids. Also, the amount of diesel fuel required makes the IGG relatively expensive. Furthermore, the combustion gas is a source of pollution when vented to the atmosphere.
The present invention solves the above problems by providing a system and method for making both utility air and inerting gas for use on a ship. The solution provided by the present invention is simple, efficient, and relatively non-polluting.